In this family, considering that \(\delta ^2 M_{(2)}=\delta ^2 J_{(2)}=0\) , we can obtain [1]}, [2]}
\(\begin{aligned}\mathcal {E}_{\Sigma _1}(g,\delta g)=-\frac{\kappa }{8\pi }\delta ^2 A_{(2)}\,,\end{aligned}\) 
